Now faith is the substance of things hoped for, the evidence of things not seen. By faith we understand that the worlds were framed by the word of God, so that the things which are seen were not made of things which are visible. Hebrews 11 1-3 NKJV
It takes faith and humility to understand that we are the creation. The Creator spoke, and it was by His words (the unseen) that the worlds were made. That is difficult to comprehend when we build things from materials that are seen.
I believe that faith is believing and trusting in the word of God. We simply take Him at His words. What He says is truth – He does not lie. In order to do that, God must speak to us. He has given us the written word and He also speaks to us in His own way (visions, spoken word, by our senses, etc.).
Hebrews goes on to tell us the accounts in which others heard from God and acted in faith (or belief) in what God said. Abel, Enoch, Noah, Abraham, etc. There is an important verse burried within.
But without faith it is impossible to please Him, for he who comes to God must believe that He is, and that He is a rewarder of those who diligently seek Him. Hebrews 11 6 NKJV
Two things stood out to me. The first is that we must believe God lives. So, faith is required to please Him. The second is that it was not just belief in Him, it is also a belief that He is a rewarder of those who diligently seek Him. God is good and it is a blessing to diligently seek Him. I ask myself why then is it so hard to diligently pursue Him when it should be my joy. This is a great part of Hebrews to keep me anchored day-to-day.
These all died in faith, not having received the promises, but having seen them afar off were assured of them, embraced them and confessed that they were strangers and pilgrims on the earth. For those who say such things declare plainly that they seek a homeland. And truly if they had called to mind that country from which they had come out, they would have had opportunity to return. But now they desire a better, that is, a heavenly country. Therefore God is not ashamed to be called their God, for He has prepared a city for them. Hebrews 11 13-16 NKJV
I have often heard Christian material that we are aliens or strangers to this world. But, this verse puts it beautifully: we desire a better/heavenly country. God has a beautiful country awaiting, which is why we should look forward to being with Him in eternity.